Quad NOR R/S latch with tri-state outputs
The CD4043BD is a Texas Instruments quad NOR R/S latch from the 4000B series, with tri-state outputs and a 1:1 circuit configuration. It integrates four independent latches in a single 16-SOIC package, each with a set (S) and reset (R) input and a common output enable (OE) that puts the outputs into high-impedance state.
Operates from a 3V to 18V supply rail, covering the full 4000B family range. Each output can source or sink 6.8 mA typical, which is sufficient to drive standard CMOS logic inputs or a low-current LED indicator directly.
Temperature grade and propagation delay
Propagation delay is 50 ns typical, which sets the maximum toggle rate — for a 50% duty cycle clock, the latch can handle up to about 10 MHz before the output fails to settle.
Supplied in a 16-SOIC package (0.154-inch width, 3.90 mm body) with surface-mount termination. The supplier device package is also 16-SOIC, so the footprint is standard — no exotic land pattern required. The tube packaging is suitable for hand-assembly or low-volume reflow.